Improvement in rotary pumps



IINITED STATES PATENT OFFICE.

A. H. KNAPP, OF- NEVTON CENTRE, MASSACHUSETTS, ASSIGNOR TO JESSE A. LOGKE, S. G. B. GOOMBS, AND DAVID H. PRIEST.

IMPROVEMENT IN ROTARY PUMPS.

.To a/ZZ zozom it may concern,.-

Be it known that I, A. H. KNAPP, of New ton Centre, in the county of Middlesex and State of Massachusetts, have invented an Improved Rotary Pump; and I do hereby de- Glare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification.

Fig. l is a side elevation of the pump; Fig. 2, a rear view thereof, the rear plate ofthe case being removed; Fig. 3, a transverse vertical section of the pump in a plane indicated by the line w fr, Fig. l; Fig. 4, alongitudinalcentral vertical section thereof.

Like Aletters designate corresponding parts in all of the figures.

My improvements are applied to that class of rotary pumps in which a piston-wheel revolves in a cylindrical case, the pistons passing a small butment which is turned within a cylindrical recess of the case by the action of the piston-wheel itself inside of the case.

In the accompanying drawings, the inclosing case is represented by A, with two removable heads, a a, at the ends, the piston-wheel by H, with two pistons, h h, on opposite sides thereof, and the butment by I, with two curvilinear or cylindro'concave grooves,i i, in

opposite sides of it for the reception of the pistons h h as they pass the butment. The piston-wheel H with its pistons h h t the inside of the case accurately, both at the ends and the periphery, so as to allow but little leakage of water by the same. The butment I also fits its recess accurately, as well as the juncture of the piston-Wheel and butment. The piston-wheel is driven by a crank, B, or its equivalent, for any power desired, applied toits shaft C outside of the case; and the movement is communicated from the pistonvvheel to the butmentby the pistons h h acting in the grooves or concavities t' i, and by cogs m m and a n, respectively, on the intermediate cylindrical surfaces of the piston-wheel and butment, between the said pistons and said grooves. The butment is situated (generally) vertically above the pistonwheel. The ends of the shafts G D of the piston-wheel and butment turn in extended bearings o c and d d of the case, and at one end of each, respectively, there are packing-caps b and f to make the pump tight at those places, the shaft C pass-` ing through its cap b, so that the power may be applied thereto. The other end of each shaft is inclosed by the rear head, a, ot' the case. The piston-wheel and its butment do not occupy the whole interior length ot' the case, but at one end there is a space occupying the Whole interior end of the case, for two waterchambers, Gand T, the former being connected With the induction-pipe through a passage, e, and the latter connected with the eductionpipe through a passage, g. These water-chambers are separated from the pistonchamber by a vertical transverse partition, E, and from eachother by a partition, S, situated obliquely, substantially as shown in Fig. 2, so that the two orices or apertures, P Q,\.vl1ich respect ively form-the communication between these l two water-chambers. and the piston-chamber, may be situated nearly at the same height and near each other, as indicated. The valve L, to prevent the water from running bark into the well or reservoir, is situated at the bottom of the water-chamber G, and closes the top of the induction-passage e, and there is a small aperture, j, through the partition E, close at the bottom of the chamber G, and thence, within the pistonchamber, a shallow passage, k, leads down, and iinally through the bottom ofthe case, to be closed or opened by a cock, K, substantially as represented. By this means the Water can be drained -from the whole pump at any time to avoid freezing, or for any other purpose; but, the passage being ordinarily closed, it does not interfere with the working of the pump. A suitable nozzle, R, is secured to the eduction passage g, generally so as to be readily removable by using a fastening screw, p, Fig. l. Hosemay be attached to the -end of the spout q, or at an orifice on the top, closed by a cap, r, Fig. l.

My improvements consist, first, in the combined arrangement of the piston-wheel H and butment I; second, in the use of the separate space, occupying the entire end of the case, for water-chambers, communicating with the induction and eductiou pipes, and, third, in the drain-aperture j and passage k, stopped by the cock K.

In considering my first improvement, I wish it to be distinctly understood that I use a simple butment, I, instead of a second pistonwheel to be operated .by the main or driving piston-wheelH. BybutmentJImeanherea simple stop or water-closer, provided only with roncavities t' i for the reception of the pistous ofthe pistonwheel, as they pass by; and, not having any pistons or projections beyond the cylindiical surface of the butment itself', for forcing water, although, of course, the concavities t' il carry around a little water,

lI move the butment by the actual gearing of wheel act, first, in the concavities of the other' wheel to turn it, and then in turn, `the concavities ot' the driving-wheel act upon thel pistons ot' the driven wheel. In the latter case the action, at first, is nearly in a radial direction as to the wheel to be driven, so that it takes an immense force to move the wheel for a short distance-so much so that, after the pistons become somewhat worn, as they quickly do, it is often impossible to start or move by the ordinary power the wheel when it arrives or stops at this dead-point position. 'l`he result is that the pumpin a short time becomes inoperative; but with my arrangement the butment is moved with nearly equal facility in all parts, the action ot the pistons in their concavities being nearlyin a tangen-V tial direction, or with a wed gin g force so great as to cause no interruption nor retardation of the motion at any point.

The advantages derived from my second improvement consist in several particulars. First, it enables the check or sustaining valve L to be located there so as not to interfere with the construction and operation of the pston-wheeland cylindrical piston-chamber, as in other rotary pumps; second, it enables access to be had to the inside of the pump and to the valve without taking the pump to pieces and unpacking its joints; third, it en` ables me to arrive at another improvement of much importance-namely, to locate the inlet height I am enabled to cause the pressure of the water on they receiving side, which acts upward against the pistons, to counteract the I am aware.,

pressure of the water on the expelling side,

Which'acts downward against the piston so that when the water is lifted a certain distance above the pump, in relation to the depth from which the water is d-rawn up, then two forces exactly counterbalance each other, thereby avoiding or obviatin g the wear upon one side only of the shaft-bearing; whereas, in other pumps, wherein the pressure is downward on both sides of the pistons, the bearings soonwear so much as to cause the pistons to drag on and wear away the interior of the case at the bottoma very seriousV evil, which soon renders the pump useless. By placing the inlet and outlet passages near and opposite to each other, and at the ends of the pistons and butment, I am enabled to save the water which is brought round in the coucavities m, andV to produce a nearly constant stream of water. Thus, by inspecting Fig. 3 it will be seen that when the piston h ,begins to enter its concavity t and to displace the. water therefrom, the outlet-aperture Q receives the expelled water, till the concavity is almost entirely closed, and then, as soon as the concavity begins to be opened again by the receding piston, itis brought over oppo-` site to the inlet-aperture P, and is filled therefrom.

What I claim as my invention, and desire to secure by Letters Patent, is-4 i l. In tbe piston and rcvolving-butment rotary pump, the employment of gearing-cogs m m and a a, respectively, upon the intermediate portions of the peripheries ofthe pistonwheel and butment, alternating in action, and inV combination with the pistons and their con- 'cavities, substantially as and for the purpose therein specified.

2. The water-chambers G T; in the end ot' the pump-case, separate from and opposite to the piston-chamber and bntment-recess, substantially as and for the purposes herein set forth.

3; The arrangement of the inlet and outlet apertures P Q, at nearly equal heights, and

near each other, in combination with the pistons and butment, substantially as and for the purposes herein specified.

`4. In combination with the piston andrevolvingbutment rotary pump, herein described, thel drain-aperture j, passage lf, and cock K, substantially as and for the purpose setlorth.

A, `H, KNAPP.

Witnesses:

D. K. PRIEs'r, S. G. B. UooMBs. 

